Topic 2 - Bonding, Structure and Propeties of Matter Flashcards
Why do ionic lattice need to a lot of energy to break their bonds?
They have a strong electrostatic attraction
Why do ionic compounds have a high melting and boiling points?
They have a strong electrostatic attractions
What can ionic compounds do when they are melted or dissolved in water?
They can conduct electricity
Why can ionic compounds conduct electricity if they’re melted or dissolved in water?
Because the charged ions are free to move
What do small molecules contain?
Strong covalent bonds
What is the problem with small molecules?
They have weak intermolecular forces
What are small molecules usually what at room temperature?
Gases or liquids
Why do small molecules have low melting and boiling points?
Because it requires little energy to overcome the intermolecular forces
What does a big molecule have that c small molecules don’t?
Strong intermolecular forces
What do bigger molecules force have because of their strong intermolecular forces?
High melting point
High boiling point
What are polymers linked by?
Strong covalent bonds
What are polymers usually what at room temperature?
Solid
Why do polymers not conduct electricity?
Because the molecules have no overall charge
What does a giant covalent bond take to overcome it?
Energy
A lot of energy to overcome the covalent bonds means that they have what?
Very high melting and boiling points
Examples of giant covalent structures?
Silicon dioxide
Diamond
Graphite
List the 3 states of matter
Solid
Liquid
Gas
What happens when a solid material is heated?
It gains energy
What happens when a solid gains energy?
It vibrates more
What are diamonds giant covalent structures made out of?
Carbon atoms
Why are diamonds hard?
They have strong covalent bonds
Do diamonds have a high or low melting/boiling point?
High
What are Graphites giant covalent bonds made up of?
Carbon atoms
What giant covalent bond is arranged in layers of hexagonal rings?
Graphite
Why can layers of graphite easily slide over each other?
They have weak intermolecular forces
What does delocalised electron mean?
The electron can be Free to move around
Why is graphite a good conductor of electricity?
It has delocalised electrons
What is Graphene ?
A single layer of graphite
Graphene has delocalised electrons so it a good at what?
Good conductor of heat and electricity
What are fullerenes?
A covalent structures with hollow shapes
Fullerene structure is based of what?
Rings of carbon atoms
Fullerenes and graphite are similar why?
That have delocalised electrons
Delocalised electrons in fullerenes make them good at what?
Good conductors of heat and electricity?
Why are fullerenes good catalyst?
They have a high surface area to volume ratio
What are carbon nanotubes?
Fullerenes with a cylindrical shape
Why are nanotubes resistant to being stretched?
Because they have a high tensile strength
What does ionic bonding join?
Metals and non-metals
What does covalent bonding join?
Non-metals together
What does metallic bonding join?
Metals together
What is an ion?
A charged atom or molecule
What does positive ions have more or what than electrons?
Protons
Negative ions have more of what?
Electrons
